Telephone call transmitter



Feb. 13, 1940. J c HELD I 2,189,944

TELEPHONE CALL TRANSMITTER Filed Oct. 9, 1937 2 Sheets-Sheet 1 INVENTOR By CF/EL 0 ATTORNEY Feb. 13, v194-0. HELD 2,189,944

TELEPHONE CALL TRANSMITTER Filed Oct. 9, 1937 2 Sheets-Sheet 2 III/7 0 1/1/11" IiI/IIIIIIIIII l INVENTOR J. C. FIE L 0 ATTORNEY Patented Feb. 13, "1940 Y j TELEPHONE CALL TRANSMITTER Joseph C. FieldyMaplewood, J., assignor to Bell Telephone Laboratories,

Incorporated,

New York, N. Y., a oorporation of New York (Application October 9, 1937,. Serial No. 168,188

.3 Claims. (01. 179-410) This invention relates to telephone call transmitter devices and especially to call transmitters of the finger-wheel operated type for use in con- .nection with so-called linemans handsets.

The object of the invention is the provision of a call transmitter of the type above referred to which will be simple, cheap to manufacture, con

venient in use andaccuratein operation.

According to the invention, a spindle which is secured to a base plateserves for supporting a speed governor mechanism, an impulse :mech

anism and a finger-wheel in superposed relation to each other, and a motor spring which is located in a recessiormed in the finger-wheel, is

' provided for returning this Wheel to normal unoperated position aftereach selective movement. Means carried by the finger-Wheel is provided for voperatively connecting the pulsing cam with the finger-wheel during the return movement of the latter to normal for opening a normally closed contact and thereby transmitting a series of pulses corresponding to the digit selected, such digits being printed on the face of a casing provided for housing the transmitter mechanism. Means in the formof a gearing mechanism is provided for operatively connecting the pulsing cam to the speed governor mechanism for controlling the movement of the finger-wheel and thereby the rotation of the pulsing cam for actuating the pulsing contact ata predetermined rate of makeand-break operation. Other features of the invention and other advantages will appear from the following description and by the claims appended thereto reference being made to the accompanying drawings in which:

Fig. 1 is a side view of a telephone linemans handset embodying the call transmitter of the.

invention, the handset being shown with portions cutaway. 1

Fig. 2 is a front View of the call transmitter.

Fig. 3 is an enlarged front view showing the casing and finger-wheel with portions cut away.

Fig. i is a partial View shownwith the fingerwheel removed from its supporting spindle and the pulsing cam with portions cut away.

Fig. 5 is a partial view shown with the fingerwheel and pulsing cam removed from their supporting spindle and the casing with portions cut away.

6-45 of Fig. 3 and Fig. '7 is a cross-sectional In the drawings I0 is a circular base plate Fig. dis a cross-sectional view taken on line raceway formed by the rim I I which is formed with a rim or drum portion- 11, shown in Figs. 5, 6 and 7-, serving as a raceway for the'weight'sfl and I3 of a centrifugal speed governor the function of which will be hereing after described in detail.

' The governor weig ts Hand i3 are mounted on the ends of ribbon springs it and it having their other ends secured in an inverted cupshaped member l6 secured to'the hub of a-pinionf i1, this pinionbeing rotatably mounted on the enlarged portion of a spindle. 18 secured t the base plate' H) and position concentricrel'ative tothe rim ll byanut I9.

On spindle i8 insuperposed relation pinion l H is rotatably mounted a gear; i X onth'e'hub of which is securedly mounted a pulsing cam 29 of insulating material. The movement of cam 29 is imparted to governor weights i2 and; 53 through a pinion 2! engagedtby the gear 99K and agear 22 engaging. the pinion H. The gear 22 is secured on the hub of pinion 2i which is inturn rotatably mounted on a spindle 23 extending perpendicularly from the base plate HI as shownin Figs. 4, 5 and 6. I W 3 On the top end of spindle I8 is rotatably mounted a finger-wheel 24 having a circular rim .25 which cooperates witha discmember 2"! to form a drum for receiving the spiral motor spring 26. the disc member 21 engaging a shoulder per-- tion in the rim 25 with a press-fit adjustment for securing it thereto. i g f One end of motor springlt is secured; to'a bushing 28 keyed to the spindle ISas shown in Fig. 6 and the other end of this spring ish'ooked to therim 25 as shownin Fig. 3 so thatthe r0- tating movement of the finger-wheel 24 in a clockwise direction will tension the motor spring 26. i

The finger-wheel Zicarries a spring pressed pawl 29 shown in- Figs.3, '4, 6 and '7 disposed in engaged relation with the pulsing cam 26 for rotating it upon the'counterclockwise movement of finger-wheel 24' as efiected by the tension of motor spring 26, a stopin the form of a pin 36 being provided for engaging the pawl 29 when in the position shown in Figs. 3 and 4 for limiting the angular movement .of the pulsing cam 20 and that of the finger-wheel 24 intheir return movement to normal position.

A spring member 40 has one of .its ends secured to thebase plate [0 by screws M and its free end frictionally engages the: inverted cup-shaped member I6 for preventing chattering of the governor weights in their cyclic movement in the An operable pulsing spring 3! and its cooperating contact 32 are mounted in a pile-up arrangement on the base plate NJ. The operable pulsing spring 3| is formed with a bentportion .1: shown in Figs. 3, 4 and 5 disposed in engaged relation with the pulsing cam 29 to serve as a check pawl for preventing the movement of the impulse cam 20 during the selective movement of the'fingerwheel 24.

The finger-wheel 24 is provided with a peripheral shoulder portion registering with a circular opening in a casing 333 provided for housing the transmitter mechanism. This housing is secured to the base plate i I! by a number of screws SC-i, SC-Z and SC-S engaging the upward extending portion Pl-P2 and P3 formed with. the base plate It). This housing is provided with a finger stop 34 shown in Figs. 2iand3 and on it are printed the digits 1 to 0 inclusive disposed in space relation and adjacent the arms Al, A2, A3, A4,

' A5, A6, A7, A8, A9 and A59 formed with the finger-wheel 24, the arms Al, A2, A3, etc. serving as finger-holds for manually operating the finger-wheel against the tension of motor spring 26.

The finger-wheel 24 is provided in position adjacent each arm Al, A2, A3, etc., with blind holds HI, H2, H3, H4, H5, H6, H7, 2-18, H9 and HIE! provided for receiving the end of a pencil, for

example, which may be used for rotating the finger-wheel in its selective clockwise movement.

The call transmitter of the invention may be placed in the receiver end of a handset HS as shown in Fig. 1 and secured in adjusted position therein iniany well-known manner, and a manually operable snap switch SS is provided for disconnecting the condenser C from the telephone receiver R and transmitter T for a purpose well known in the telephone art.

In a typical example of call transmitting operation the turning movementof the finger-wheel 24 an angular distance from any One of the digits appearing on the housing 33 to the finger stop 34 is eiTective to move the pawl 29 idly on the pulsing cam 28 and simultaneously tension the motor spring 26, the pulsing cam being prevented from turning during this movement of the fingerwheel by the pulsing spring 3! having its toothshaped portion :1: engaging oneof the teeth of the cam. Upon the release of the finger-wheel, the pawl 29 is effective to rotate the pulsing cam an angular distance corresponding to the selective "movement of the finger-wheel when the pawl 29 engages the stop pin 39. The return movement of finger-wheel 34 to normal and the consequent operation of impulse cam 28 and that of the gear 19X carried thereby is effective to rotate the pinion Zl and the gear 22 secured thereto for rotating the governor weights:through the engagement of gear 22 with the pinion H. The spring arm 40 which frictionally engages the inverted cup-shaped member I6 prevents the so-called chattering of the weights in their cyclic movement in the raceway formed by the rim I l and thereby permits a uniform operation of the pulsing cam and that of the contact actuated thereby.

What is claimed is:

1. A call transmitter comprising a mounting plate, a spindle secured to said mounting plate, a pulsing cam mounted for rotating movement on said spindle, said cam having ratchet-shaped impulse camimounted for unidirectional movement as a unit on said spindle, a finger-wheel mounted for rotary movement on said spindle and movable thereon in directions opposite to each other, a motor spring tensioned by theoperation of said finger-wheel in one of said directions, means carried by said finger wheel engaging said cam for actuating it upon the return movement of said finger-wheel under the tension of said spring but ineffective relative to said cam upon the movement of said finger-wheel in the other di- 3 rection, a pulsing contact actuated by operation of the cam upon said return movement of said finger-wheel to normal, and a governor mechanism actuated by the operation of said gear for controlling the operation of said cam.

3. A call transmittercomprising a mounting plate, a spindle secured to said plate, a gear and a pulsing cam mounted for movement as a unit on said spindle, another spindle secured to said plate, a pinion and a gear mounted for movement on the last-mentioned spindle, said pinion engaging the first-mentioned gear, a drum carried by said plate, a governor mechanism in said drum having a pinion engaging the last-mentioned gear, a finger-wheel rotatably mounted on said spindle for movement in directions opposite to each other, a spring tensioned by the operation of said wheel in one of said directions, and means carried by said finger-wheel for operatively engaging said cam for rotating it under control of said mechanism upon the movement of said wheel in the other of said directions, and a pulsing spring actuated by the operation of said cam.

JOSEPH C. FIELD. 

